This invention relates to open top, bottom dump railway cars for use in transporting lading such as coal and ore in bulk. While the car is particularly adapted for mine service, it also may be utilized in general rail service.
In U.S. Pat. Nos. 3,211,305 and 3,487,963 bottom dump cars are disclosed in which the bottom is hingedly connected to the car side along one edge of the side. During dumping the car body is supported allowing the non-hinged portion of the bottom to open for lading discharge.
In U.S. Pat. No. 3,529,734 an inclined bottom car is provided in which the car body is hingedly mounted on a first side of the car. The opposite side of the car is lifted to discharge lading below the side of the car being lifted.
In U.S. Pat. No. 3,331,517 a bottom dump car has a front portion including a bottom inclined toward the center of the car. The rear portion of the car is hingedly mounted on the front portion. The rear portion has a curved bottom which is raised relative to the front portion to discharge lading between the wheels of the car.
In U.S. Pat. No. 3,790,008 the bottom of the car is composed of clam-shell doors which are pivotally mounted about opposite ends of the car body. During unloading the clam-shell doors pivot in opposite directions to allow lading discharge between the wheels. However this arrangement does not make efficient use of the volume available for carrying lading. To discharge between the rails, the side walls are inclined inwardly, resulting in lost capacity in the car below the inclined side walls. If the sides are vertical, the transverse distance between the sides must be less than the distance between the rails, to obtain lading discharge between the rails. This also limits the carrying capacity of the car.
In U.S. Pat. No. 1,825,943 a mine car is disclosed in which transversely spaced body sections which abut and overlap in the mid portion of the car are pivotably mounted about longitudinally spaced end members. The lading is unloaded between the rails when the body sections are pivoted about the end members to the open position. However in this construction the body sections each include diagonal plates 29 and 30, extending longitudinally and transversely of each body section. The car volume beneath these diagonal plates carries no lading. Thus the carrying capacity of the car is reduced by the car volume under these diagonal plates.
In U.S. Pat. No. 2,042,266 transversely spaced side sections which extend outboard of the rails are pivotably mounted about longitudinally spaced end sections. In addition a longitudinally extending underframe includes a bottom which is pivotably mounted about one end of the car and latched to the other end of the car. To discharge lading the side sections are pivoted about the end sections to discharge lading outside the rails and the bottom is unlatched to discharge lading between the rails.
This design requires pivoting and latching structure for the bottom which increases the cost of the car.